Many life science and diagnostic assays often involve parallel processing of a large number of samples. Liquid handling is an important part of most assays. The development of automated liquid handling systems has brought improved efficiency and safety to laboratory workflow.
Efficiency is mostly achieved by the use of automated robotic workstations. Various workstations are available from vendors, such as the BRAVO™ workstation from Agilent Technologies, Inc. (Santa Clara, Calif.). The main parts of such robotic workstations include automatic liquid handling systems. An automated liquid handling system can provide high throughput and automated processing of liquid samples.
An automated liquid handling system typically includes one or more pipettors arranged as an assembly that can transfer a liquid sample from a source to the desired locations in the work area. For example, FIG. 1 shows a schematic of a liquid handling system (pipetting instrument) 100, which includes a single gantry 101 that controls the movements of pipettor 102. The pipettor 102 can typically move in the X. Y, and Z axis directions. To enable these movements, the pipettor 102 is arranged on a track (not shown) that allows the pipettor 102 to move in the Y axis direction (the direction in-and-out of the plane of the drawing), and the gantry 101 is arranged on a track 105 such that the gantry can move in the X-axis direction (left and right in this view). After moving to the desired plate 103 on the work platform in the pipetting instrument 100, the pipettor 102 can move in the Z-axis direction (up-and-down direction in this view) to aspire or deliver a liquid sample.
The single pipetting group (single gantry) liquid handling system as illustrated in FIG. 1 (or a variation of this configuration) is used in current commercial liquid handling system, such as Biomek™ FX from Beckman-Coulter, Inc. (Brea, Calif.), Freedom EVO™ from Tecan Group, Ltd. (Switzerland), and STAR Line™ from Hamilton Company (Reno, Nev.).
A new system with two blocks on an arm of a robot manipulator is disclosed in U.S. Patent Application Publication No. 2007/0264725. Each block contains two or more pipettes with rigid spacings between them to accommodate well spacings of the existing microtiter plates. The two blocks may be interleaved or interlaced, thereby halving the spacings between the pippetes.
While these prior art liquid handling systems have proven useful, there remains a need for more flexible liquid handling systems.